Surgeon&#39;s bone screw driver



c. A. BOYER sURGEoNs BONE scREw DRIVER March 2 1943. A

Filed July 27, 1942 Patented Mar. 2, 1943 UNITED .STATES PATENT orgie e.

2,312,869 sURGEoNs BONE sonnw parvint Charles A. B'o'yer, WinonaV Lake, Ind.

Application July 127, `194.2, :Serial No. 452,417

c Claims. (ci. 145-52) This invention relates to a 'surgeons bone screw driver, and its principal object is to provide a screw driver of this character which is conveniently and economically manuac'turable, conveniently and efficiently utilizable in consonance with professional work, and eiectively sterilizable.

Other objects and advantages will hereinafter appear.

This device is an improvement upon the screw driver shown and described in my copend-ing 'patent application, iiled May 4, 1942, Serial #441,689.

1n the accompanying drawing- Fig. `1 is a Ageneral elevation-of the surgeons bone screw driver constituting the invention, showing it as it appears while in engagement with its independent `locking device.

Fig..2 is a general elevation of the Vscrew driver, without its independent locking device.

Fig. 3 is -a fragmentary cross-sectional elevation, in an enlarged scale, showing the combined terminals of the screw driver and its locking device in operative positionof locked engagement with the screw-head.

Fig. 4 is a fragmentary transverse-sectional 'elevation of the screw driver, taken on rline 4-4 of Fig. 3.

Fig. 5 is a fragmentary elevation, inY an enlarged scale, showing the terminal of the screw driver, without its locking device.

` Fig. 6 is a top plan view 'of the terminal 4of l the screw driver, as it appears in Fig. 5.

Fig. 'l is a fragmentary elevation, in an Aenl'arged scale, showing the terminal o"f the independent locking device.

Fig. 8 is a top plan view 'of the 'terminal "of `screw-slot I I and presses thereagainst under tension produced'by the cooperation of its prongs IIii-with the cam 8, in the manner shown in Fig. 2. For coaction with the screw driver I there -isprovided a locking device I2, Fig'. 1, compriswhich is so configurated that it provides a symmetrical cammed member 8. Within the slot 6, and in embracement with the member 8, there is insertible a screw-driving blade 9, Figs. 3, 4, 9, having a pair of laterally springy prongs I0 adapted to press against the cammed sides 8a of member 8 in such manner that the latter normally maintains the working part 9a of the blade 9 within the cup 4 and projecting beyond the shank 3, as illustrated in Fig. 5. When the ing a tube I3 having at one end ahead I4 with a bayonet slot I5, and at its opposite terminal a slot I6, Figs. 7, 8, with a lateral enlargement I1 and a shoulder I8 at its tip, as illustrated.

'The slot I5 is of a width corresponding to the base-portion I9 of screw-shank 1, the enlarged opening -ll of said slot is ample to permit lateral entry within the tube I3 of -the screw'- head 5, and t-he shoulder I8 is provided for the retention of said head, in the manner shown in Figs. 1-4. The shank 3 of screw driver I is slidable Within the bore 20 of tube I3, and carries a pin 2l for operative engagement with the bayonet slot I5 of the locking device I2.

When it is desired to initially drive the surgical screw 'I partially into place, it is rst inserted into the terminal of tube I3 of locking device I2 by laterally passing its base-portion I9 and head 5 through the slot I5 and the opening Il, andthe screw is then held to bear its underside against the shoulder I8 of said terminal, in the position shown in Figs. 1, 3, 4. Thereupon, the shank 3 of the screw driver is slid longitudinally into the bore 20 of tube I3 and its blade 9 vdirected to venter rthe head-slot the pin 2-I simultaneously entering the vertical `portion I5a of the bayonet Aslot I5. The handle 2 is then turned partially, t'o cause the pin 2, I to -about upon the transverse inclined shoulder lb of bayonet slot I5l to compel the blade/"39 to'ent-er the-screw-slot I I, under tension as'above described, and-force'the screw-head 5to bear with its underside against the shoulder I8 of the locking devicev VI2,l in which manner the surfgical screw -1 becomes frmly locked vto the lscrew driver in operative state.

In performing the delicate surgical operation of fastening broken bones or fastening plates on broken bones, it is vital to initially insert the screw and thread it partially and accurately into `precise location, and to thereafter drive it entirely home with care, skill, and freedom from impediments. For this purpose, therefore, the surgical screw 'l having been rrnly secured to the screw driver as above described, the implement of the invention may be then utilized by the surgeon to initially thread the screw into 1ocation as required. The screw driver is then released and disengaged from the bayonet-slot connection of the locking device I2, and is slid outwardly from the bore 20 thereof and entirely removed from the device. The device I2 is then removed from the partially threaded screw by slipping it away laterally from the head 5 and shank-portion I9 thereof. Thereupon, the surgeon returns the screw driver proper to the partially threaded screw, and inserting itsblade 9 into the head-slot I I he applies the implement in a normal manner to drive the screw home fully. In thus threading in of the screw, the cupped terminal part 4, surrounding the blade 9, assures a irm hold of the screw-head 5 Aand prevents accidental disengagement of the yblade from screwslot II, and should circumstance or impediment render it difcult or impossible to retain in regshank having therein aslot extending from its terminal and configurated to form a cam, a screw driving blade longitudinally slidable in said slot having a springy prong engaging said cam, said cam normally causing said prong to maintain said -blade with the operative portion thereof projecting exteriorly of said terminal, said blade when pressed inwardly into said slot being under tension by the pressure of said prong upon said cam, and said blade being adapted to app-ly said tensional pressure upon the screw-head while projected in its screw-slot.

3. A screw driver for a slot-headed screw including the combination of a handle-mounted terminal and coniigurated to form a cam, a screw istry the axes of the screw driver and the screw- Y the former may be deviated and the 'efficient threading -of the screw neverthelesscontinued, with the cupped part 4 embracing the screw-head to prevent separation of the blade 9 from headslot I I and the tensional pressure of the blade within the slot, resulting from coaction of the prongs I0 and cam 8, assuring an axial application of pressure of the blade upon the screw.

The blade 9 is readily removable completely from the shank 3 by merely withdrawing it longitudinally out of the slot 6 and embracement of its prongs I0 with the cam 8, the prongs spreading apart sufficiently to disengage from the cam. It will be noted therefore that this entire implement consists of but three integral parts I,

I2, 9 that :are conveniently separable from each other, and due thereof and the general character of the formation of these parts, as seen from the illustration in the drawing, the entire implement may be eilectively sterilized in connection with the operation, in accordance with medical requirements. l

Variations may be resorted to within the scope of the invention, and portions of the improvements may be used without others.

Having thus described my invention, I claim:

1. A surgeons bone screw driver for a surgical slot-headed screw, including the combination of aV handle-mounted shank provided with a cupped terminal for receiving the screw-head, said shank having therein a slot extending from said terminal and congurated to form a cam, -a screwdriving blade longitudinally slidable in said slot having a pair of springy prongs-engaging said cam, said cam normally causing said-prongs to maintain said blade with the operativeportion4 thereof vprojecting exteriorly of lsaid terminal, said blade when pressedinwardlyinto said slot-being undertension by the pressure of said prongs upon ,said cam, and said blade being adapted to Yapply .said tensional pressure .upon the screw-head while projected in its screw-slot.v

2. A screw driver for a slot-headed screw in- ,.cluding the combination of a handle-,mounted ,ing the screw to said blade comprising a tube for `therethrough passing said shank, the terminal of shank having therein a slot extending from its vof said terminal, said blade when pressed inwardly into said slot being under tension by the pressure of said prong upon said cam, and said blade being entirely withdrawable from said slot and shank by its prong being disengageable from said cam.

4. A screw driver as in claim 2 having in coaction therewith an independent device for locking the screw to said blade comprising a tube for therethrough passing-said shank, the terminal of said tube having means for therein inserting the screw-head laterally with a shoulder for receiving the underside of the screw-head, and means upon said tube and shank for therewith locking said blade withinthe slot of the screw-head, with said 4head pressed against said shoulder, and with said blade pressing in the screw-slot under tension of said cam and prongs.

5. -A screw driver as in claim 2 having in coaction therewith an independent device for locksaid tube having means for therein inserting the .screw-head with means for receiving the underside of the screw-head, and means upon said tube and shank Afor therewith locking said blade withu in the slot .of the screw-head, with said head pressed against said receiving means, and with -the blade pressing in the screw-slot under tension of said cam and prongs.

6. A screw driver as in claim 3 having a coac- 'tion therewith an independent device yfor locking the screw tosaid blade comprising a tube for therethrough passingsaid shank, the terminal of Vsaid tube -having means for therein inserting the screw-head with means for receiving the under- -.side.of.. the screw-head, and means upon said tube andshank for therewith locking said blade within the slot vof the screw-head, with said head pressed against said receiving means, and with the blade pressing inthe screw-slot under tension of said cam and prongs.

CHARLES A'. BOYER. 

